LECTURE 3 bony thorax, pectoral girdle, thoracic cage

Question 1

axial skeleton

Answer 1

skull (cranial and facial bones), vertebrae, ribs, sternum

Question 2

appendicular skeleton

Answer 2

bones of upper and lower limbs, girdle bones (scapula, clavicle, pelvis)

Question 3

the bony thorax

Answer 3

sternum, ribs, 2 clavicle, 2 scapula, vertebrae

Question 4

pectoral girdle

Answer 4

scapula and clavicle on each side, attaches upper extremity to axial skeleton, holds upper extremity away from skeleton for mobility

Question 5

mobile articulations of pectoral girdle

Answer 5

acromioclavicular, sternoclavicular

Question 6

borders of thoracic cage

Answer 6

thoracic vertebrae posteriorly; ribs posteriorly, anteriorly, and laterally; sternum, ribs and costal cartilages anteriorly

Question 7

functions of thoracic cage

Answer 7

forms protective cage around heart, lungs, and other organs; mobile for respiration; muscle attachment

Question 8

parts of sternum

Answer 8

manubrium, body (gladiolus), xiphoid process

Question 9

features of manibrium

Answer 9

jugular (sternal) notch, sternal angle - 2nd rib

Question 10

articulations of manibrium

Answer 10

costal cartilages of ribs 1-2

Question 11

feature of body of sternum

Answer 11

xiphosternal joint

Question 12

articulations of body of sternum

Answer 12

costal cartilages of ribs 2-7

Question 13

features of xiphoid process

Answer 13

hyaline cartilage prenatally, eventually becomes bone (40 years); muscle attachment

Question 14

pairs of ribs

Answer 14

12 pairs total, ribs 1-7 true ribs, ribs 8-12 false ribs, ribs 2-9 typical ribs, ribs 1, 10-12 atypical ribs

Question 15

true ribs

Answer 15

ribs 1-7, each has its own costal cartilage for attachment to sternum

Question 16

false ribs

Answer 16

ribs 8-10, have more than one costal cartilage for attachment to sternum (indirect)

Question 17

floating ribs

Answer 17

ribs 11-12, have no attachment to sternum

Question 18

typical ribs

Answer 18

ribs 2-9, attach to 2 thoracic vertebrae at 3 sets of facets (S, I and transverse costal facets)

Question 19

atypical ribs

Answer 19

ribs 1, 10-12, attach at only a single costal facet on each side of 1 thoracic vertebra, 11-12 also do not articulate with a transverse costal facet

Question 20

rib anatomy (typical ribs)

Answer 20

head, neck, tubercle, angle, shaft/body, subcostal groove

Question 21

typical rib articulation

Answer 21

dorsal attachment to thoracic vertebrae, head of rib -> 2 costal facets (superior costal facet, inferior costal facet of vertebra above it, intervertebral disc), tubercle of rib -> transverse costal facet

Question 22

exterior intercostal muscles

Answer 22

origin: inferior border of rib above; insertion: superior border of rib below; fibers run oblique (down and forward); aid in inspiration (elevate ribcage, increase dimension)

Question 23

internal intercostal muscles

Answer 23

origin: superior border of rib below; insertion: inferior border of rib above; fibers run at right angles to external intercostals; aid in expiration (depress ribcage, decrease dimensions)

Question 24

innermost intercostal muscles

Answer 24

subcostals, transversus thoracis; attachments similar to internal intercostals, attach ribs; small, variable, function unclear

Question 25

neurovascular bundle of intercostal muscles

Answer 25

intercostal VAN supplies intercostal muscles in intercostal space; sit in subcostal groove (protected); between internal intercostal and innermost intercostal layers